Friction shock absorber



May 18, 1948. DENTLER 2,441,621

- E A "A mu: 1 H l2 FRICTION SHOCK ABSORBER Filed March 11; 1946 Inn e72,107: flrnold Ellen/Zen i M. AM 121% Patented May 18, 1948TRIGIIONS'BOCK ABSORBER Arnold *E. :Dentier, La Grange, -:.I'll.,'assignor eto :H. Miner-rind, Qhicago, 1111., -.a'-corporationnit-Delaware npplica tioniMarchg-fl, 194e, serialatasha ".16 Glaims.

ThisfiHVEHtiOHI'GlEtfiS-FUO improvements in friction-shock absorbers,especially adapted-for snub hing-"the actionof=truck springs of;railway-s ears.

One: object of the inven-t'ion is=to provide a friction shockabsorber}Of the character indicated comprising a fric'tionmember, --a pair offriction elements having movement lengthwise with respect "tosaid"memberyandspring means opposing relativemovementof-saidelements andmember toward each other,-whereinthe-friction member and elements havelengthwise extending, interengaging-friction-surfacesand-the frictionelements are forced into tight'frietiona-l-contactwith isaid-member bytorsional springmeans reacting between said 'elementstendingto rotatethe latter *withresp'ectto each other.

Another object of -the*invention is "to provide a friction shockabsorbercomprising'a'iriction casing, a. pair of friction elements slidinglytelescoped within the casing, spring means yieldingly opposinglengthwise movement of the "friction elements inwardly of the .casingand "torsional spring means anchored to said "friction. elementsrespectively and "tending-to rotatethe same with respect "to each otherto hold said elements in tight frictional contact *with the. frictionmember.

A more specific obj ect {of :the invention .is to providea shockabsorber as set {orthin the precedin pa a ranhywhe ei the asing nd tion-elements are provided with :intererl a ing friction surfaces of,'suchformati'on as "to. restrict said casing and elementsto movement.in" lengthwise direction -=with-respeetxjto ;each other and presentengagingrfacesrwhich are; pressed, against each other byfitheiactionoitthe torsional spring means. V

Gther objects of the invention will more fcl arly appearfromthe'description and claims 'hereinaiterffoillowing.

-In'thedrawingforming a partof'tihis specificationf-Figu're 1 iris a"centraL' longitudinal, ,vertiqal sectional view my filIlDIDVQd shockabsorber. Figure 2is a top plan view of Figure, 1. 'TFigIJIeSB is ahorizontal sectional view, correspondingsubs'tantia-llyto'thelirre'fl3q'oil figuregl; Figure 4 isa'imrizontalsectionalview;correspondingsubstantially to thejline i 1- 4;ofil'l ligure 1,, with the spring means which opposes .relative movementomitted. *Fi'gme 5" is aitop plan view of the 'friction shellor casingof my improved shock 531bsorber.

R.e'ferrin to the drawingyrnyomproved shock absorber, comprisfisibroadlya casingiAi a set-of two. ffriction elements B and C iorming 'a'itwopiece plunger .jtelescoped :within the; c s n a;

"torsional spring-bar]?reacting'between the friction lelements and aspring resistance E yieldinglyopposing relative movement of the. two.fric tionelements toward the-easing.

The' friction'cas-i-ngA is in the form-of-a. cylindricaL'tubular memberhaving: an annulanl laterally outwardly projecting-flange it at itslowerend forming, in effect, a follower member. The casing A- is open atthe-top-and the-interior wall of said-casing is provided-with -a seriesof longitudina'lly -extending, .annu-larly arranged, grooves jection ofthetopspring plate of the truck pringll of V-s-haped, transverse crosssection. The grooves ll being arranged i-n annular series, the casingthus presents an-interior contour of star shapedtransverse crosssection. The side walls of each groove H provide opposed, longitudinallyextending, substantially flat friction surfacesl'2- l2. The bottom ofthe casing is closed'by a transverse "wall 13, which is --pr.ovioledwith a downwardly opening seat 14 adapted to receive the'spri ngcentering projection of the lower spring follower'plateof the truckspringcluster. 1 The friction element Bis inthe form ofa tubular shellhaving--21. laterally-projecting, annular flange-i5 at; its top endcorresponding in diameter to the 'follower formed'by the flange H1 ofthe-casing A, and forms, in effect, a follower flange member. The shellBis open at the bottom end and is provided with a plurality oflongitudinally extending, exteriorribs "-I '6 -'l-6 ofV-shap ed,transverse cross section'onthe exterior thereof. The ribs f|'6| 5correspond innumber to the grooves l '|--'I l ofthe casing -Aa-nd-slidingly interfit therewith. The sides of each V-shapedrib l6present two longitudinally extending, flat friction surfaces "-41, whichengagethe surfaces 12-42 verse wall :l8gprovided with an upwardlyopeningse'at l9 which receivesthe spring centering pro cluster.

The fri ion a tubularshellandis' of'the same diameteras the shellportion of the elementB and is provided with lengthwise extending ribs202 0 of :V- shaped, transverse cross section, similar 'to'rthe ribs ,l6-." l 6 of the element '3 and corresponding innumber to the ribs l6.The-ribs" also interfit with the grooves H of the casing A and presentlongitudinally extending, fiat friction surfaces 21- 2! .on oppositesides thereof engaging the opposed surfaces l2-l*2 ofthe grooves 'l l.The bottoms-end .of the shell-like element 0 is closed :by

a transverse'WaII-ZL-theelement C -thus;present- 7 element C is also intheform of' ing a cup-shaped formation. As shown most clearly in Figure1, the element C is disposed below the element B in slightly spacedrelation thereto and is connected to the latter by the torsion springBar D, which is preferably of square cross section. The spring bar D isfixed to the elements B and C respectively, having its upper and lowerends welded thereto, the upper end of said bar being seated in a squareopening 23 in the wall 18 of the element B and the lower end beingseated in a square opening 24 provided in the bottom wall 22 of theelement C. The elements B and C together form a plunger which istelescoped within the cas ing A with the ribs of the elements B and Cengaged within the grooves of the casing, the element C being turnedabout the longitudinal central axis of the mechanism with respect to theelement B to twist the bar D, as shown in Figures" 1 and 3, and placesaid bar under tension. As will be evident, the torsional spring barthus reacts between the elements B and C, tending to turn these elementsin opposite directions with respect to each other, thus forcing thesurfaces of the ribs of these elements into tight frictional contactwith the friction surfaces presented by the grooves I l of the casing A.

The spring E is in the form of a heavy helical coil surrounding thecasing A and the shell portion of the element B and having its top andbottom ends bearing respectively on the flange [5 of the element B andthe flange H] of the casing A.

My improved shock absorber is substituted for one or more of the coilspring units of a cluster of truck springs, the same being interposedbetween the top and bottom spring'follower plates of said cluster.

The operation of the improved shock absorber is as follows: Upon thespring cluster of the railway car truck being compressed between the topand bottom spring follower plates, the two piece plunger formed by thefriction elements B and C is moved downwardly; lengthwise with respectto the casing A, against-the resistance of the spring E. The desiredsnubbing action is thus produced during compression of the device bysliding frictional contact between the friction surfaces of the V-shapedribs of the elements B and C and the friction surfaces of the grooves ofthe casing A, these friction surfaces being held in tight contact by thetorsional action of the spring D, which tends to turn the elements B andC in reverse directions with respect to each other. The frictionalresistance produced is substantially constant throughout the compressionand recoil strokes of the device. During recoil of the truck springs,expansion ofthe spring E returns all of the parts of the shock absorberto the normal position shown in Figure 1. As will be evident, thefrictional resistance provided between the friction elements and thecasing being constant during all phases of operation of the shockabsorber, the same amount of frictional resistance to snub the action ofthe truck springs is produced during both compression and recoil of thetruck springs.

From the preceding description taken in connection with the drawing, itwill be evident that, although the casing and friction elements havebeen shown and described as provided with interengaging grooves andribs, similar results may be obtained by employing a casingof square orrectangular interior cross section and 3, correspondingly shapedtwo-piece plunger comprising a pair of friction elements, which are heldin frictional contact with the casing by a torsional spring which reactsbetween said elements to turn the tion with a friction member; of a setof two friction elements, said elements being telescoped with saidmember for lengthwise sliding movement with respect thereto, said memberand each of said elements having interfitting guide portions extendinglengthwise thereof and limiting said elements-to lengthwise movementwith respect to said member, said interfitting guide portions presentinglengthwise extending, cooperating friction surfaces; torsional springmeans reacting between said elements tending to rotate one of saidelements with respect to the other and press the friction surfacesthereof into tight frictional contact with the friction surfaces of saidmember; and spring means yieldingly opposing relative movement of saidelements and member toward each other.

2. In a friction shock absorber, the combination with a friction member;of a set of two friction elements concentric with said member andtelescoped with the same for movement with respect thereto lengthwise ofthe mechanism, said member and each of said elements having interfittingguide portions extending lengthwise thereof and limiting said elementsto lengthwise movement with respect to said member, said interfittingguide portions presenting lengthwise extending, cooperating frictionsurfaces; a torsional spring bar anchoring one of said elements to theother for movement in unison lengthwise of the mechanism, said springbar being under torsional stress and tending to rotate one of saidelements with respect to the other and press the friction surfacesthereof into tight frictional contact with the friction surfaces of saidmember; and spring means yieldingly opposing relative movement of saidelements and member toward each other.

3. In a friction shock absorber, the combination with a friction casing;of a two part friction plunger telescoped within said casing forlengthwise movement, said casing and each of said parts of the plungerhaving interfitting guide portions extending lengthwise thereof andlimiting said parts of the plunger to lengthwise movement with respectto the casing, said interfitting guid portions presenting lengthwiseextending, cooperating friction surfaces; torsional spring meansreacting between said parts of said plunger tending to rotate one partwith respect to the other and press the friction surfaces thereof intotight frictional contact with the friction surfaces of said casing; andspring means yieldingly opposing relative movement of said plunger andeasing toward each other.

4. In a frictionshock absorber, the combination with a, friction casing;of'a two part, transversely divided friction plunger slidinglytelescoped within the friction casing for lengthwise movement, saidcasing and each of said parts of the plunger having interfitting guideportions extendin lengthwise thereof and restricting said parts of theplunger to lengthwise movement with respect to said casing, saidinterfitting portions presenting lengthwise extending, cooperatingfriction surfaces; torsional spring means reacting between said parts ofthe plunger tending to rotate one .of. said partsawvithmespect $0thecother and: press: thecfrictionesunfaces lthereof int'o'itightfrictional 1 contact "with the :friction rsurf-aceslrof said casing iand sprin means wyieldinglysopposing 'relative i-movementof:saidzplungerand casing toward each other.

5. In a friction shock absorber, the =--combi:nation-v with a friCfiOn'CaSiIl'gixjflajwgipaptzplunger divided transversely 'into"innerandnouter friction elements, 'slidingly telescoped within saidfirictioncasing for lengthwise movement; said-:casing and each of said-e1ementshaving interiitting -=guide portions extending lengthwise thereo'fandrestricting said elements to length-wise movement with respect to the-casing saiil inter fitting poi tions presenting lengthwiseexten'ding,cooperat ing friction surf-aces; torsional spring-=meansanchoring said elements toeach' otl-ier for lengthwise movement inunisonand reacting between said elements tending to ro'tate-one of saidelements-with respect to 'the oth'er -andpress the friction surfacesthereof into tight frictional contact with the-friction surfaces ofthecasingyan'd spring means yieldingly opposing relative-movement ofsaid plunger an'd 'casingtowardeach other.

6. In a friction-shock='absorber;-thecombination with africtioncasinghaving'interior, lengthwise extending guidefigrooves-presenting-lengthwise extending friction'surfaces; "of a two-part plungertelescoped within the-casing forlengthwise movement, each ofsaid*partspf the plunger having guide projections extending lengthwisethereof interfitting with saidguidegrooves, said projections presentinglengthwise extending friction surfacesengaging the frictionTSUlfHiCGSTOf said casing; torsional springmeans reacting between saidparts of the -=plunger tending to "rotate one part with respect to theother aiidpress the friction surfaces thereof into tight frictionalcontact with the friction surfaces of said casing; and spring means:yieldingly opposing relative movement of said plungerand" casing towardeach other.

'7. In afriction shock absorber, the .C.0mbiniation with a frictioncasinghaving' inter'ion'length- 'wise extending gui'deways of V-shaped,transverse cross section presenting friction surfaces; of a two part,transversely divided. plunger slidingly telescoped within the frictioncasing for lengthwise movement, said parts of the plunger havinglengthwise extending guide projections of V-shaped, transverse crosssection interfitting with said guide grooves and presenting frictionsurfaces engaging the friction surfaces of said grooves; torsionalspring means reacting betweensaid parts of the plunger tending to rotateone of said parts with respect to the other and press the frictionsurfaces thereof into tight frictional contact with the frictionsurfaces of said casing; and spring means yieldingly opposing relativemovement of said plunger and casing toward each other.

8. In a friction shock absorber, the combination with a friction casingof star-shaped, transverse, interior cross section, presenting fiat,lengthwise extending, interior friction surfaces; of a two part plungerdivided transversely into inner and outer friction elements, saidfriction elements being of an exterior, transverse, cross sectionalcon-tour to slidingly telescope within said casing in interfittingrelation, said friction elements presenting friction surfacescooperating with the friction surfaces of the casing; torsional springmeans anchoring said elements to each 6 7 otheriforlengthwise; movementin unison and: re acting between said elements tending :to rotate oneofsaidfelements with respect' to the other and.

press- 'the 'friction" surfaces thereof into tight Jfrictional contactwith the friction surfaces of the casingprandz-ispring means 'yieldinglyopposingrelative movement of said plunger and casing toward each other.1

' 9. Ina fric.tionshock absorber, the combinav tionwith africtionmeniber; of-a set oftwo 'friction elements, said elementsbeingtelescoped with said member 'for lengthwise sliding movement withrespect thereto, said member and each-of said elements havinginterfitting guide portions extending lengthwise thereof andlimitingsaid elements -to lengthwisemovement with respect to said-member, saidinterfitting guide-portions pre scn'ting lengthwise extending,cooperating friction surfaces; torsionalspring means comprising anelongated spring bansaid bar ha-Vingitsoppositeends rigidly fixed tosaid elements respectively 'between said elements tending to rotateone-.ofsaid elements with respect to the otherand press the frictionsurfacesthereof into-'tight frictional contact with the frictionsurfaces of said member; and spring means yieldingly opposingrelative-movement of said elements and member toward-each other. i

In a friction shock absorber," the combinationwith a friction-member; ofa set of two friction elements concentric with said member andtelescoped with the same for movement with respect thereto lengthwise ofthe mechanism, said member and each of said elements havinginterfittingguide portions extending lengthwise thereof andlimiting said'elements tolengthwise-movementwith respect'to said member; said interfit tingguide-portions presenting lengthwiseextenm ing, cooperating frictionsurfaces; a torsional spring barhavi'ngits opposite'ends rigidlyconnected to saidel'ements respectively anchoring one 'of said elementsto the other for movement in unison. lengthwise of the mechanism, saidspring-bar 'beingunder torsional stress and tendin-g to-rotate one ofsaid elements with respect tot he other and press the friction surfacesthereof' into tight frictional contact with the friction surfaces ofsaid member; and spring means yieldingly opposing relative movement ofsaid elements and member toward each other.

11. In a friction shock absorber, the combination with a frictioncasing; of a two part friction plunger telescoped within said casing forlengthwise movement, said casing and each of said parts of the plungerhaving interfitting guide portions extending lengthwise thereof andlimiting said parts of the plunger to lengthwise movement with respectto the casing, said interfitting guide portions presenting lengthwiseextending, cooperating friction surfaces; a torsional spring bar havingits opposite ends rigidly anchored to said parts of the plungerrespectively and reacting between said parts of saidplunger tending tonotate one part with respect to the other and press the frictionsurfaces thereof into tight frictional contact with the frictionsurfaces of said casing; and spring means yieldingly opposing relativemovement of said plunger and easing toward each other.

12. In a friction shock absorber, the combination with a frictioneasing; of a two part, transversely divided friction plunger slidinglytelescoped within the friction casing for lengthwise movement, saidcasing and each of said parts of the plunger having interfitting guideportions extending lengthwise thereof and restricting said parts of theplunger to lengthwise movement with respect to said casing, saidinterfitting portions presenting lengthwise extending, cooperatingfriction surfaces; a torsional spring bar having its opposite endsrigidly secured to said parts of the plunger respectively and reactingbetween said parts of the plunger tending to rotate one of said partswith respect to the other and press the frictionv surfaces thereof intotight frictional contact with the friction surfaces of said casing; andspring means yieldingly opposing relative movement of said plunger andeasing toward each other,

13. In a friction shock absorber, the combination with a frictioncasing; of a two part plunger, divided transversely into inner and outerfriction elements, slidingly telescoped within said friction casing forlengthwise movement, said casin and each of said elements havinginterfitting guide portions extending lengthwise thereof and restrictingsaid elements to lengthwise movement with respect to the casing, saidinterfitting portions presenting lengthwise extending, cooperatingfriction surfaces; a spring bar having its opposite ends rigidly securedto said elements respectively, said bar being twisted to tension thesame and reacting between said elements tending to rotate one of saidelements with respect to the other and press the friction surfacesthereof into tight frictional contact with the friction surfaces of thecasing; and spring means yieldingly .opposing relative movement of saidplunger and casing toward each other.

14, In a friction shock absorber, the combination with a friction casinghaving interior, lengthwise extending guide grooves presentinglengthwise extending friction surfaces; of a two part plunger telescopedWithin the casing for lengthwise movement, each of said parts of theplunger having guide projections extending lengthwise thereofinterfitting with said guide grooves, said projections presentinglengthwise extending friction surfaces engaging the friction surfaces ofsaid casing; a torsional spring bar having its opposite ends rigidlysecured to said parts respectively and reacting between said parts ofthe plunger tending to rotate one part with respect to the other andpress the friction'surfaces thereof into tight frictional contact withthe friction surfaces of said casing; and spring means yieldinglyopposing relative movement of said plunger and casing toward each other.

15. In a friction shock absorber, the combination with a friction casinghaving interior, lengthwise extending guideways of V-shaped, transversecross section presenting friction surfaces; of a two part, transverselydivided plunger slidingly telescoped within the friction casing forlengthwise movement, said parts of the plunger having lengthwiseextending guide projections of 'V- shaped, transverse cross sectioninterfittin with said guide grooves and presenting friction surfacesengaging the friction surfaces of said grooves; a torsional spring barhaving its opposite ends rigidly secured respectively to said parts ofthe plunger and reacting between said parts of the plunger tending torotate one of said parts with respect to the Other and press thefriction surfaces thereof into tight frictional contact with thefriction surfaces of said casing; and spring means yieldingly opposingrelative movement of said plunger and casing toward each other.

16. In a friction shock absorber, the combination with a friction casingof star-shaped, transverse, interior cross section, presenting flat,lengthwise extending, interior friction surfaces; of a two part plungerdivided transversely into inner and outer friction elements, saidfriction elements being of an exterior, transverse, cross sectionalcontour to slidingly telescope within said casing in interfittingrelation, said friction elements presenting friction surfacescooperating with the friction surfaces of the casing; a torsional springbar having its opposite ends rigidly secured respectively to saidelements and reacting between said elements tending to rotate one ofsaid elements with respect to the other and press the friction surfacesthereof into tight frictional contact with the friction surfaces of thecasing; and spring means yieldingly opposing relative movement of saidplunger and casing toward each other.

ARNOLD E. DE NTLER.

